KitchenAid refrigerator not cooling

KitchenAid
KSRL25FTST01
Refrigerator and freezer not cooling

I noticed a small water puddle near my freezer door. I opened the freezer door and noticed everything was thawing and all the ice was melting. Then a couple hours later the refrigerator was also warm. I tested the capacitor and starter relay and they were both good. The evaporator fan was running, but not the condenser fan or the compressor. I installed a new condenser fan motor, but it didn’t run. I finally checked the voltage at the wiring input to the compressor and the reading was 6-7V not 120V. I checked my outlet and the power cord and there were no issues with them. Is there anything else that would keep the condenser fan motor and compressor from turning on besides faulty control board? Would a faulty defrost thermostat or thermistor cause that? This refrigerator is approximately 20 years old and I have read that the control board has been discontinued.

For this issue, if there is no power getting to the compressor or the condenser fan motor then the control board will be faulty. The control board has been discontinued by the manufacturer but there is a link for the part number. You can try to see if you can have yours repaired or see if you can locate a used one online.
https://www.appliancepartspros.com/whirlpool-control-assy-wp2321724-ap6007327.html